|Method and apparatus for measuring frequency and phase difference - NON|
A system for deriving direct digital indications of frequency and phase difference between two incoming pulse trains adaptable for collision avoidance systems or the like. A pair of radar beams 152 and 152A are directed toward a target 153 and corresponding beams 154 and 154A returning therefrom are detected. A digital difference circuit 110 forms a pulse train 66 from the Doppler shift frequencies of each beam pair having a repetition rate functionally related to the difference in magnitude of ...
Keywords: SOLAR ARRAYS; STEPPING MOTORS; PATENTS
|STS FACILITY AND EQUIPMENT DESIGN PLAN. VOLUME 81: COMMUNICATIONS - NON|
No Abstract Available
Keywords: CRYSTAL GROWTH; RIBBONS; SILICON; DESIGN ANALYSIS; EQUIPMENT SPECIFICATIONS; SOLAR ARRAYS
|Review of the Bioastronautics Data Book - Bottomley, T. A., Jr.|
No Abstract Available
Keywords: ELECTRICAL PROPERTIES; PANELS; SOLAR ARRAYS; CONFERENCES; ELECTRIC POWER; MANAGEMENT PLANNING
|Comparison of the Effects of using Tygon Tubing in Rocket Propulsion Ground Test Pressure Transducer Measurements - Farr, Rebecca A.|
This paper documents acoustics environments data collected during liquid oxygen- ethanol hot-fire rocket testing at NASA Marshall Space Flight Center in November- December 2003. The test program was conducted during development testing of the RS-88 development engine thrust chamber assembly in support of the Orbital Space Plane Crew Escape System Propulsion Program Pad Abort Demonstrator. In addition to induced environments analysis support, coincident data collected using other sensors and meth...
Keywords: SOLAR ARRAYS; LENSES; PHOTOVOLTAIC CELLS; CONCENTRATORS; SPACE MISSIONS; HARDWARE
|Solid-state non-volatile electronically programmable reversible variable resistance device - NON|
A solid-state variable resistance device (10) whose resistance can be repeatedly altered by a control signal over a wide range, and which will remain stable after the signal is removed, is formed on an insulated layer (14), supported on a substrate (12) and comprises a set of electrodes (16a, 16b) connected by a layer (18) of material, which changes from an insulator to a conductor upon the injection of ions, covered by a layer (22) of material with insulating properties which permit the passage...
Keywords: ELECTRIC POTENTIAL; LOADS (FORCES); PHOTOVOLTAIC CELLS; SOLAR ARRAYS; PATENTS
|Viking Lander antenna deployment mechanism - Hopper, K. H.|
One of the mechanisms that is included in the configuration of the Viking Mars Lander is an antenna dish deployment mechanism which utilizes a mechanical escapement device for controlling deployment. The criteria require that the mechanism be capable of deploying the antenna under a wide range of aiding and retarding winds after landing on Mars but must limit the acceleration during deployment and latching of the antenna...
Keywords: ACTUATORS; MECHANICAL DRIVES; SOLAR ARRAYS; MECHANICAL ENGINEERING; PERFORMANCE TESTS; SERVICE LIFE; STRUCTURAL DESIGN
|Design of a walking robot - Whittaker, William|
Carnegie Mellon University's Autonomous Planetary Exploration Program (APEX) is currently building the Daedalus robot; a system capable of performing extended autonomous planetary exploration missions. Extended autonomy is an important capability because the continued exploration of the Moon, Mars and other solid bodies within the solar system will probably be carried out by autonomous robotic systems...
Keywords: CONTROL STABILITY; CONTROLLERS; HUBBLE SPACE TELESCOPE; POINTING CONTROL SYSTEMS; SOLAR ARRAYS; COMPUTERIZED SIMULATION; FLAPPING
|Very low cost thin film CdS-Cu2S solar cell development using chemical spraying - Samara, G. A.|
A chemical spray process for the production of thin film CdS-Cu2S solar cells is discussed that is projected to cost less than 60/kW in very large scale production. The average efficiency of these cells has been improved from less than 0.3% in 1971 about 4.5% at present. Further developments for the process are considered to raise the efficiency, and to attain long life stability.
Keywords: LOW COST; MANUFACTURING; SILICON; SOLAR ARRAYS; CRYSTAL GROWTH; HEAT TREATMENT; RECRYSTALLIZATION; SHEETS
|Development of a microbalance suitable for space application - Patashnick, H.|
The tapered element oscillating microbalance (TEOM), an ultrasensitive mass measurement device which is suitable for both particulate and vapor deposition measurements is described. The device can be used in contamination measurements, surface reaction studies, particulate monitoring systems or any microweighing activity where either laboratory or field monitoring capability is desired. The active element of the TEOM consists of a tube or reed constructed of a material with high mechanical quali...
Keywords: LOW COST; SILICON; SOLAR ARRAYS; CARBON; COMPUTER PROGRAMS; FREE ENERGY; MOLECULAR DYNAMICS; MOLECULAR ENERGY LEVELS
|On-pad crew safety: Modifications to operations and hardware to improve crew escape times - Knaff, P. R|
No Abstract Available
Keywords: ENERGY POLICY; LOW COST; SILANES; SOLAR ARRAYS; GAS CHROMATOGRAPHY; HYDROGENATION; PHOTOVOLTAIC CONVERSION
|Developing A Web-based User Interface for Semantic Information Retrieval - Berrios, Daniel C.|
While there are now a number of languages and frameworks that enable computer-based systems to search stored data semantically, the optimal design for effective user interfaces for such systems is still unclear. Such interfaces should mask unnecessary query detail from users, yet still allow them to build queries of arbitrary complexity without significant restrictions. We developed a user interface supporting semantic query generation for Semanticorganizer, a tool used by scientists and enginee...
Keywords: SOLAR ARRAYS; INTERNATIONAL SPACE STATION; ELECTRIC POTENTIAL; SPACE STATION POWER SUPPLIES; ORBITS; SHORT CIRCUITS
|A compendium of hypokinetic and hypodynamic animal studies - Pleasant, L. G.|
This compendium organizes and summarizes the scientific literature dealing with the study of hypokinetic and hypodynamic animal studies. It includes both American and foreign research papers.
Keywords: SEMICONDUCTORS (MATERIALS); SILANES; SILICON; SOLAR ARRAYS; PLANT DESIGN; POWDER (PARTICLES); TEST FACILITIES
|Effects of Hydrogen on GRCop-84 - Ellis, David L.|
This report is a section of the final report on the GRCop-84 task of the Constellation Program and incorporates the results obtained between October 2000 and September 2005 when the program ended. GRCop-84 contains approximately 5.5 wt% Nb. Nb can react with H and embrittle easily. Previous work had indicated the thermodynamic possibility that Cr 2 Nb could react with H and form niobium hydrides in the presence of high pressure H such as seen in the Space Shuttle Main Engine...
Keywords: MISSION PLANNING; SPACE FLIGHT; PAYLOADS; ORBIT INSERTION; LAUNCHING; PARACHUTE DESCENT; SEQUENCING; SOLAR ARRAYS; ACCURACY; DEPLOYMENT; PROCEDURES
|EFFECTS OF SUPERPLASTICITY OF TITANIUM AND ITS ALLOYS AND THE USE OF THIS PHENOMENON IN WELDING IN THE SOLID STATE - SHORSHOROV, M. K.|
SUPER PLASTICITY OF TITANIUM AND SOME OF ITS ALLOYS ARE DISCUSSED, AS WELL AS THE POSSIBILITY OF USING TITANIUM FOR INTENSIFYING THE PROCESS BY WHICH A COMPOUND IS FORMED IN THE SOLID STATE. IT WAS ASSUMED THAT INTENSIFICATION IN WELDING DEPENDS ON THE SPEED OF THE MOVEMENT OF STRUCTURAL DEFECTS, INTERGRAIN SLIP, AND DIFFUSION. THE STUDY WAS PERFORMED ON THE IMASH-5 S-65, A DEVICE FOR HIGH TEMPERATURE METALLOGRAPHY WITH A CHAMBER ADAPTED FOR WELDING AND DILATOMETRIC PROCESSES.
Keywords: MISSION PLANNING; RENDEZVOUS SPACECRAFT; SOLAR ELECTRIC PROPULSION; SOLAR ARRAYS; SPACECRAFT POWER SUPPLIES; SYSTEMS ANALYSIS; WEIGHT ANALYSIS
|Antimatter propulsion, status and prospects - Howe, Steven D.|
The use of advanced propulsion techniques must be considered if the currently envisioned launch date of the manned Mars mission were delayed until 2020 or later. Within the next thirty years, technological advances may allow such methods as beaming power to the ship, inertial-confinement fusion, or mass-conversion of antiprotons to become feasible. A propulsion system with an ISP of around 5000 s would allow the currently envisioned mission module to fly to Mars in 3 months and would require abo...
Keywords: ENCAPSULATING; GASKETS; LAMINATES; FABRICATION; FLAT PLATES; LIFE (DURABILITY); MODULES; SOLAR ARRAYS; ADHESIVES; COST ESTIMATES; ELASTOMERS
|Drives and benefits overview - Mcintyre, S. D|
The major technology issues for an advanced orbital transfer vehicles (OTV) engine to be used in conjunction with a space based, reusable orbit transfer vehicle are discussed. The results of the space station studies as they relate to the OTV and the ground rules and guidelines for a reusable OTV vehicle study are reviewed. The technology drives and benefit categories such as mission versatility, increased reliability or reduced cost are presented...
Keywords: INFRARED SPECTRA; TEMPERATURE MEASUREMENT; MODULES; PERFORMANCE TESTS; SOLAR ARRAYS; TRANSPARENCE; EFFICIENCY; IRRADIANCE; REFLECTANCE; SPECTRUM ANALYSIS
|An Extensible Schema-less Database Framework for Managing High-throughput Semi-Structured Documents - Maluf, David A.|
Object-Relational database management system is an integrated hybrid cooperative approach to combine the best practices of both the relational model utilizing SQL queries and the object oriented, semantic paradigm for supporting complex data creation. In this paper, a highly scalable, information on demand database framework, called NETMARK is introduced. NETMARK takes advantages of the Oracle 8i object-relational database using physical addresses data types for very efficient keyword searches o...
Keywords: SOLAR ARRAYS; VAPOR DEPOSITION; THIN FILMS; SUBSTRATES; SOLAR CELLS; ELECTRICAL PROPERTIES; MODULATION; POLYCRYSTALS; FABRICATION
|Effects of Thermomechanical History on the Tensile Behavior of Nitinol Ribbon - Lach, Cynthia L.|
Shape memory alloys (SMAs) have enormous potential for a wide variety of applications. A large body of work exists on the characterization of the microstructure and stress-strain behavior of these alloys, Nitinol (NiTi) in particular. However, many attributes of these materials are yet to be fully understood. Previous work at NASA Langley Research Center (LaRC) has included fabrication of hybrid composite specimens with embedded Nitinol actuators and modeling of their thermomechanical behavior...
Keywords: INTERNATIONAL SPACE STATION; SOLAR ARRAYS; SPACE STATION POWER SUPPLIES; GIMBALS; ELECTRIC GENERATORS; PHOTOVOLTAIC CONVERSION
|Preliminary feasibility assessment for Earth-to-space electromagnetic (Railgun) launchers - Rice, E. E.|
An Earth to space electromagnetic (railgun) launcher (ESRL) for launching material into space was studied. Potential ESRL applications were identified and initially assessed to formulate preliminary system requirements. The potential applications included nuclear waste disposal in space, Earth orbital applications, deep space probe launchers, atmospheric research, and boost of chemical rockets. The ESRL system concept consisted of two separate railgun launcher tubes (one at 20 deg from the horiz...
Keywords: ELECTRIC BATTERIES; SOLAR ARRAYS; SPACECRAFT POWER SUPPLIES; COMMUNICATION CABLES; REGULATORS; VOLTAGE CONVERTERS (DC TO DC)
|Environmental impact analysis with the airspace concept evaluation system - Augustine, Stephen|
The National Aeronautics and Space Administration (NASA) Ames Research Center has developed the Airspace Concept Evaluation System (ACES), which is a fast-time simulation tool for evaluating Air Traffic Management (ATM) systems. This paper describes linking a capability to ACES which can analyze the environmental impact of proposed future ATM systems. This provides the ability to quickly evaluate metrics associated with environmental impacts of aviation for inclusion in multi-dimensional cost-be...
Keywords: MARS PATHFINDER; MARS ROVING VEHICLES; DUST; SOLAR ARRAYS; MARS ENVIRONMENT; SPACECRAFT SHIELDING; TRANSPARENCE; DEPOSITION
|Message Passing vs. Shared Address Space on a Cluster of SMPs - Shan, Hongzhang|
The convergence of scalable computer architectures using clusters of PCs (or PC-SMPs) with commodity networking has become an attractive platform for high end scientific computing. Currently, message-passing and shared address space (SAS) are the two leading programming paradigms for these systems. Message-passing has been standardized with MPI, and is the most common and mature programming approach...
Keywords: CONSTRAINTS; CORDAGE; KEVLAR (TRADEMARK); SPACECRAFT EQUIPMENT; SOLAR ARRAYS; LAUNCH VEHICLE CONFIGURATIONS
|Method for ambiguity resolution in range-Doppler measurements - NON|
A method for resolving range and Doppler target ambiguities when the target has substantial range or has a high relative velocity in which a first signal is generated and a second signal is also generated which is coherent with the first signal but at a slightly different frequency such that there exists a difference in frequency between these two signals of Delta f(sub t). The first and second signals are converted into a dual-frequency pulsed signal, amplified, and the dual-frequency pulsed si...
Keywords: ELECTRIC BATTERIES; ELECTRIC DISCHARGES; ELECTRIC POTENTIAL; SOLAR ARRAYS; DESIGN ANALYSIS; EARTH ORBITAL ENVIRONMENTS
|Assessment of the international workshop on CdS solar cells - Boer, K. W|
General problems relating to the basic understanding of CdS/Cu2S solar cell operation, to material aspects of the cell and to manufacturing methods and cell engineering are discussed.
Keywords: CRYSTAL GROWTH; RIBBONS; SEMICONDUCTING FILMS; SILICON; PHOTOVOLTAIC CELLS; PRODUCTION ENGINEERING; SOLAR ARRAYS
|Inertial navigation/calibration/precise time and frequency capabilities - Galloway, L. M.|
The Aerospace Guidance and Metrology Center was conceived in 1959 to be the US Air Force Inertial Navigation and Metrology Center. This paper will show the mission capabilities of the Inertial Navigation Maintenance Center and the Air Force Measurement and Standards Laboratory. Highlighted will be the precise time and frequency program developed by AGMC to support Air Force precise time and frequency requirements worldwide...
Keywords: CONFERENCES; UTILITIES; FLAT PLATES; SOLAR ARRAYS; ELECTRIC NETWORKS; FAILURE ANALYSIS; PHOTOVOLTAIC CELLS; REFINING; SILICON; THIN FILMS
|Representativeness Uncertainty in Chemical Data Assimilation Highlight Mixing Barriers - Lary, David Joh|
When performing chemical data assimilation the observational, representativeness, and theoretical uncertainties have very different characteristics. In this study we have accurately characterized the representativeness uncertainty by studying the probability distribution function (PDF) of the observations. The average deviation has been used as a measure of the width of the PDF and of the variability (representativeness uncertainty) for the grid cell...
Keywords: LOW EARTH ORBITS; SPACECRAFT CHARGING; SOLAR CYCLES; SOLAR ARRAYS; GROUND TESTS; ELECTRIC CURRENT; HIGH VOLTAGES
|Surface topographical changes measured by phase-locked interferometry - Lauer, J. L.|
An electronic optical laser interferometer capable of resolving depth differences of as low as 30 A and planar displacements of 6000 A was constructed to examine surface profiles of bearing surfaces without physical contact. Topological chemical reactivity was determined by applying a drop of dilute alcoholic hydrochloric acid and measuring the profile of the solid surface before and after application of this probe...
Keywords: NICKEL HYDROGEN BATTERIES; REGENERATIVE FUEL CELLS; BROMINE; CHLORINE; HYDROGEN; OXYGEN; SOLAR ARRAYS
|Robust UHTC for Sharp Leading Edge Applications - Levine, Stanley R.|
Ultrahigh temperature ceramics have performed unreliably due to material flaws and attachment design. These deficiencies are brought to the fore by the low fracture toughness and thermal shock resistance of UHTCs. If these deficiencies are overcome, we are still faced with poor oxidation resistance as a limitation on UHTC applicability to reusable launch vehicles. We have been addressing the deficiencies of UHTCs for the past year via a small task at GRC that is part of the 3rd Gen TPS effort...
Keywords: STRUCTURAL DESIGN; SOLAR CELLS; SOLAR ARRAYS; WINGS; STRETCHING; MECHANICAL ENGINEERING; DEEP SPACE 1 MISSION
|American Space History: Legacies, Questions, and Opportunities for Future Research - Siddiqi, Asif A|
In the 35 years since astronauts Neil A. Armstrong and Buzz Aldrin set foot on the Moon, no space achievement has quite captured people s imaginations as Apollo. Thirty-five years after that singular event, the specter of Apollo still looms large as a benchmark for all that came later. In the context of the current inertia of the American space program-the Space Shuttle temporarily grounded while astronauts take to orbit in Russian rockets for unimaginative tours of the International Space Stati...
Keywords: SOLAR ARRAYS; SOLAR ENERGY; SOLAR POWERED AIRCRAFT; SUNLIGHT; PHOTOVOLTAIC CELLS; SOLAR CELLS; INDUSTRIES; ORGANIZATIONS; RESEARCH AIRCRAFT
|Fabrication feasibility study of a 30 watt pound roll-up solar array Quarterly report, 27 Jun. - 30 Sep. 1967 - King, W. G|
Structural design and analysis of 30 watt/pound roll-up solar array
Keywords: FABRICATION; FEASIBILITY; PRODUCT DEVELOPMENT; SOLAR ARRAYS; SOLAR CELLS; STRUCTURAL DESIGN; PRODUCT DEVELOPMENT; SOLAR CELL; STRUCTURAL DESIGN
|Analytical modeling of spacecraft power systems - Cassinelli, J|
Power system components are reviewed. Battery and solar array models are discussed. Shunt regulators, dc-dc converters, and cabling are also discussed.
Keywords: ARC HEATING; PRODUCTION ENGINEERING; REFINING; SILICON; HIGH TEMPERATURE TESTS; SOLAR ARRAYS; SYSTEMS ANALYSIS; TEST FACILITIES
|Retrieval of Polar Stratospheric Cloud Microphysical Properties from Lidar Measurements: Dependence on Particle Shape Assumptions - Reichardt, J.|
A retrieval algorithm has been developed for the microphysical analysis of polar stratospheric cloud (PSC) optical data obtained using lidar instrumentation. The parameterization scheme of the PSC microphysical properties allows for coexistence of up to three different particle types with size-dependent shapes. The finite difference time domain (FDTD) method has been used to calculate optical properties of particles with maximum dimensions equal to or less than 2 mu m and with shapes that can be...
Keywords: DATA ACQUISITION; POINTING CONTROL SYSTEMS; PERFORMANCE TESTS; HUBBLE SPACE TELESCOPE; SOLAR ARRAYS
|Theoretical study of the upper ionosphere based simultaneous data from the ISIS satellites and from the CNET incoherent backscatter sounder - Fleury, L|
No Abstract Available
Keywords: HYDROGENATION; SEMICONDUCTORS (MATERIALS); SILANES; SOLAR ARRAYS; PARTICLE SIZE DISTRIBUTION; REACTION KINETICS; REACTOR TECHNOLOGY; TEMPERATURE MEASUREMENT
|Bubble Measuring Instrument and Method - NON|
Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer. respectively. The image transducer frequency is much higher than the pump transducer frequency...
Keywords: MARS (PLANET); MARS MISSIONS; MARS PATHFINDER; MARS ENVIRONMENT; MARS ATMOSPHERE; MISSION PLANNING; DUST; SOLAR ARRAYS
|SOLAR ELEMENTS BASED ON HETEROJUNCTION OF P-TYPE GAAS(1-X)PX AND N-TYPE GAAS - CHEBAN, A. G.|
MEASURED DARK CURRENT-VOLTAGE CHARACTERISTICS, LIGHT CURRENT-VOLTAGE CHARACTERISTICS UNDER LOAD, AND SPECTRAL RESPONSE CURVES ARE GIVEN FOR PHOTOSENSITIVE ELEMENTS PREPARED BY LIQUID EPITAXIAL GROWTH OF P-TYPE GAAS/1-X/P/X/ ON AN N-TYPE GAAS SUBSTRATE. DUE TO THE ABSENCE OF A CONDITIONING SURFACE LAYER, 30% OF THE RADIATION INCIDENT ON THE WORKING SURFACE IS REFLECTED, YIELDING AN EFFICIENCY OF 6 TO 7%...
Keywords: CONTROL EQUIPMENT; INSTRUMENT ORIENTATION; SATELLITE-BORNE INSTRUMENTS; SOLAR ARRAYS; BREADBOARD MODELS; CIRCUITS; SYSTEMS ENGINEERING
|SiC/SiC Composites for Applications Above 2600 F - DiCarlo, James A.|
Using data from panels with 2D woven architectures,t his presentation describes progress in identifying advanced constituent materials and processes for achieving a high conductivity SiC/SiC composite system with long-term structural life under oxidizing conditions at 2600 degrees F. A key factor for this progress is the development of approaches at NASA GRC that allow the constituent SiC fiber and SiC matrix to display high thermal conductivity, high creep-rupture resistance and high microstruc...
Keywords: SPACECRAFT CHARGING; EXTERNAL SURFACE CURRENTS; CONFERENCES; SPACE PLASMAS; COMPUTERIZED SIMULATION; TETHERLINES; SOLAR ARRAYS; CHARGE DISTRIBUTION
|Land Surface Temperature Measurements from EOS MODIS Data - Wan, Zhengmin|
We have developed a physics-based land surface temperature (LST) algorithm for simultaneously retrieving surface band-averaged emissivities and temperature from day/night pairs of moderate resolution imaging spectroradiometer (MODIS) data in seven thermal infrared bands. The set of 14 nonlinear equations in the algorithm is solved with the statistical regression method and the least squares fit method...
Keywords: SOLAR ARRAYS; SOLAR CELLS; MARS PATHFINDER; ANGLES (GEOMETRY); INCIDENCE; DATA PROCESSING; DATA ACQUISITION
|NASA Connect - ISS - ISS Basics - NASA LaRC Office of Education|
NASA Connect segment exploring the International Space Station. The video explains the basic facts and statistics about the ISS.
Keywords: NASA Connect; International Space Station; ISS; Solar Arrays; Space Stay; Atlantis; Destiny Laboratory; Research; ISS Components
|Intelligent Pilot Aids for Flight Re-Planning in Emergencies - Pritchett, Amy R|
Experimental studies were conducted with pilots to investigate the attributes of automation that would be appropriate for aiding pilots in emergencies. The specific focus of this year was on methods of mitigating automation brittleness. Brittleness occurs when the automatic system is used in circumstances it was not designed for, causing it to choose an incorrect action or make an inaccurate decision for the situation...
Keywords: ELECTRIC PROPULSION; PROPULSION SYSTEM CONFIGURATIONS; MARS MISSIONS; LASER POWER BEAMING; SOLAR ARRAYS; COST EFFECTIVENESS; SPACECRAFT DESIGN
|Pressure distribution on Joukowski wings - Blumenthal, O|
The hydrodynamics and mathematical models as applied to the potential flow about a Joukowski wing are presented.
Keywords: RECTENNAS; SOLAR POWER SATELLITES; SYSTEMS ANALYSIS; FAILURE ANALYSIS; SOLAR ARRAYS; SPACECRAFT COMMUNICATION; STRUCTURAL DESIGN
|The recirculation flow pattern of a VTOL lifting engine - Schwantes, E|
A method is developed to predict theoretically the increase of temperature due to wind recirculation in the inlet of a VTOL aircraft lift engine exhausting normally to the ground. A method for calculating the velocities in the recirculation flow is presented. The laws of spread of buoyant plumes is used to calculate the temperatures within the recirculated flow. The three regions of the propulsion jet are identified as: (1) the free jet, (2) the wall jet, and (3) the zone of separation of the wa...
Keywords: ATTITUDE (INCLINATION); LIQUID METALS; SOLAR ARRAYS; DIELECTRIC PROPERTIES; ELECTRIC CONTACTS; GALLIUM; PERFORMANCE TESTS; RING STRUCTURES
|Fan Stall Flutter Flow Mechanism Studied - Lepicovsky, Ja|
Modern turbofan engines employ a highly loaded fan stage with transonic or low-supersonic velocities in the blade-tip region. The fan blades are often prone to flutter at off-design conditions. Flutter is a highly undesirable and dangerous self-excited mode of blade oscillations that can result in high-cycle fatigue blade failure. The origins of blade flutter are not fully understood yet. Experimental data that can be used to clarify the origins of blade flutter in modern transonic fan designs a...
Keywords: ATMOSPHERIC PRESSURE; SOLAR ARRAYS; SPRAYERS; VAPOR DEPOSITION; THIN FILMS; PHOTOVOLTAIC CELLS; AIR MASSES; TECHNOLOGY UTILIZATION; SUBSTRATES; SOLAR CELLS
|Aerospace medicine and biology: A continuing bibliography with indexes (supplement 325) - NON|
This bibliography lists 192 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during June, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance.
Keywords: PHOTOVOLTAIC EFFECT; SILICON ALLOYS; SOLAR ARRAYS; SPACECRAFT POWER SUPPLIES; FABRICATION; HIGH ALTITUDE BALLOONS; LOW COST; THIN FILMS
|Fluorinated epoxy resins with high glass transition temperatures - Griffith, James R|
Easily processed liquid resins of low dielectric constants and high glass transition temperatures are useful for the manufacture of certain composite electronic boards. That combination of properties is difficult to acquire when dielectric constants are below 2.5, glass transition temperatures are above 200 C and processability is of conventional practicality. A recently issued patent (US 4,981,941 of 1 Jan...
Keywords: ELECTRICITY; OXIDES; RARE GASES; SOLAR COLLECTORS; EMITTERS; ENERGY CONVERSION; NARROWBAND; PHOTOVOLTAIC CELLS; SOLAR ARRAYS; THERMAL ENERGY; GAS MIXTURES; NUCLEAR REACTORS
|A Subsurface Soil Composition and Physical Properties Experiment to Address Mars Regolith Stratigraphy - Richter, L.|
Previous in-situ measurements of soil-like materials on the surface of Mars, in particular during the on-going Mars Exploration Rover missions, have shown complex relationships between composition, exposure to the surface environment, texture, and local rocks. In particular, a diversity in both compositional and physical properties could be established that is interpreted to be diagnostic of the complex geologic history of the martian surface layer...
Keywords: METAL FILMS; SPACECRAFT POWER SUPPLIES; PROTECTIVE COATINGS; INDIUM OXIDES; TIN OXIDES; MAGNESIUM FLUORIDES; OXIDE FILMS; POLYMERS; SPACECRAFT CHARGING; SOLAR ARRAYS
|Space Telemetry for the Energy Industry - NON|
Space telemetry is the process whereby information acquired in orbit is relayed to Earth. In 1981, Bill Sheen, President of Nu-Tech Industries, Inc., saw a need for a better way of monitoring flow, due to high costs of oil and gas, increasing oil field theft and a mounting requirement for more timely information to speed up accounting procedures. Sheen turned to NASA for assistance which was provided by Kerr Industrial Applications Center (KIAC)...
Keywords: ELECTROSTATICS; HIGH VOLTAGES; SOLAR ARRAYS; SPACECRAFT CHARGING; ELECTRIC POTENTIAL; POWER LINES; TRANSMISSION LOSS; NASA SPACE PROGRAMS; SPACECRAFT DESIGN
|Some Effects of Horizontal-Tail Position on the Vertical-Tail Pressure Distributions of a Complete Model in Sideslip at High Subsonic Speeds - Alford, William J., Jr|
An investigation has been made in the Langley high-speed 7- by 10-foot tunnel of some effects of horizontal-tail position on the vertical-tail pressure distributions of a complete model in sideslip at high subsonic speeds. The wing of the model was swept back 28.82 deg at the quarter-chord line and had an aspect ratio of 3.50, a taper ratio of 0.067, and NACA 65A004 airfoil sections parallel to the model plane of symmetry...
Keywords: FEEDFORWARD CONTROL; STRUCTURAL VIBRATION; VIBRATION DAMPING; POINTING CONTROL SYSTEMS; SHAPE CONTROL; SOLAR ARRAYS; ACTUATORS; STEPPING MOTORS; INPUT
|Insulation commonality assessment (phase 1), volume 1: Section 1.0 through 6.0 - Schroeder, C. J|
The insulation commonality assessment study was performed to consolidate all the data associated with insulation designs. The scope of the study was limited to the designs associated with the S-2 stage, S-2 derivatives, and technology studies. Data were gathered for various insulation designs and organized into a design manual format. The results of phase 1 are also reported.
Keywords: PLASMA DYNAMICS; SATELLITE SOLAR ENERGY CONVERSION; SOLAR ARRAYS; SPHINX; DATA ACQUISITION; MISSION PLANNING; SATELLITE CONFIGURATIONS; SPACE MISSIONS
|Non-reflecting boundary conditions for the compressible Navier-Stokes equations - Abarbanel, S.|
A small perturbation analysis, in the long wavelength regime, is used to obtain the downstream boundary condition for the pressure for the flow over a flat plate. The methodology is extendable to other geometries. Numerical results for high Reynolds number laminar flows show great improvement in convergence rate to steady state as well as the quality of the results.
Keywords: CHEMICAL BONDS; ADHESION; ADHESIVE BONDING; INTERFACIAL ENERGY; DELAMINATING; ELECTRONIC MODULES; ENCAPSULATING; FLAT PLATES; INTERFACES; PHOTOVOLTAIC CELLS; SILICONES; SOLAR ARRAYS
|GPS-Based Navigation And Orbit Determination for the AMSAT AO-40 Satellite - Davis, George|
The AMSAT OSCAR-40 (AO-40) spacecraft occupies a highly elliptical orbit (HEO) to support amateur radio experiments. An interesting aspect of the mission is the attempted use of GPS for navigation and attitude determination in HEO. Previous experiences with GPS tracking in such orbits have demonstrated the ability to acquire GPS signals, but very little data were produced for navigation and orbit determination studies...
Keywords: HIGH VOLTAGES; SOLAR ARRAYS; TECHNOLOGY UTILIZATION; SOLAR ELECTRIC PROPULSION; AEROSPACE SYSTEMS; MECHANICAL DRIVES; GROUND TESTS; ENCAPSULATING; PLASMA INTERACTIONS
|Digital Images and Human Vision - Watson, Andrew B|
Processing of digital images destined for visual consumption raises many interesting questions regarding human visual sensitivity. This talk will survey some of these questions, including some that have been answered and some that have not. There will be an emphasis upon visual masking, and a distinction will be drawn between masking due to contrast gain control processes, and due to processes such as hypothesis testing, pattern recognition, and visual search.
Keywords: SYSTEMS ANALYSIS; SOLAR ENERGY CONVERSION; SOLAR ARRAYS; MEASURING INSTRUMENTS; DESIGN ANALYSIS; COMPUTER PROGRAMS; INTERNATIONAL SPACE STATION; TELEMETRY